A few weeks later, it was time for the first Quidditch match of the year: Gryffindor vs. Slytherin. Harry, who was one of the Gryffindor players, didn't seem to have an appetite at breakfast. Ron and Seamus tried to coax him to eat while Nico watched from further down the table.

"Harry seems nervous," Nico noted unsympathetically.

"I don't blame him," Neville replied. "It's always the Seekers that get clobbered."

"What's that mean, Seeker? Everyone keeps going on about it."

"That means it's his job to find the Golden Snitch," Neville explained. "Catching it ends the game and wins a hundred and fifty points for the Seeker's team, so they usually win."

"Then what's the point of all the other players?" Nico asked, confused.

Neville shrugged. "Most Cups rank teams by total points earned over the season, not total matches won. So if you've got a team that came really close to winning several matches, and another team that won one match but got steamrollered in several others, then the first team places higher."

"Huh. Cool." Nico took another bite of toast.

"You hate flying, but now you're interested in Quidditch?" Hermione asked, a glint of amusement in her eyes.

Nico swallowed his mouthful. "Just because I can't play, that doesn't mean I can't have fun watching."

"And here I wasn't sure you even understood the concept of fun," Hermione teased.

Nico sobered. "Yeah, well, my favorite card game got my sister killed, so that kind of ruined it for me."

Neville gave him a weird look. "A card game got your sister killed?"

"Long story."

"Oh." There was an awkward pause. "I'm sorry about your sister."

"Thanks."

Having effectively killed the conversation, Nico finished his breakfast in silence. Hermione and Neville joined him when he stood up to go to the Quidditch pitch. They passed Harry on their way out of the Great Hall.

"Good luck, Harry," Neville said. "You're gonna do great."

"Thanks," Harry replied, staring at his full plate.

Nico smiled nastily. "I hear Seekers get attacked a lot. I look forward to seeing you knocked off your broom."

"Oh, shove off," Harry snapped. Nico turned and continued walking.

"That was uncalled for," Neville reproached.

"Don't expect me to be nice to him just because he's some sports star," Nico said grumpily.

Out in the Gryffindor section of the stands, they found seats by Leo Valdez. Fred and George were both on the team, so Leo was sitting by himself.

"Is it just me, or is it warmer on this bench?" Neville asked.

"I modified it to have built-in heating," Leo replied proudly. "Spectate in comfort, my friends."

"You modified it?" Hermione asked curiously. "How?"

"Science, engineering, a touch of fire magic and pure genius." Leo pulled a pair of quills and some wire out of his pocket and began fiddling with them. "Fred and George kept dragging me to all their practices last year, so I've ended up making a lot of improvements to the stands."

"Like what?" Nico wondered.

"I've got a remote control that can eject the teachers from their seats, create a smokescreen around the field, or shower the players in potato chips."

"Potato chips?" Hermione repeated in disbelief.

"Crisps to you Brits." Leo gave his quill-and-wire contraption an experimental spin. It briefly floated in the air, then gently landed in his lap.

"You're weird," Neville stated. "In a good way."

Leo flashed him an impish grin. "So I've been told."

Soon, the players walked onto the field, seven from each house. The Gryffindors wore red and the Slytherins wore green. Madam Hooch, the referee, stood in the middle of the field with her broomstick and her whistle. She spoke briefly to the team captains before the players mounted their brooms. Then she blew her whistle, and the game began.

Nico tried to follow what was happening, but the players moved very quickly and he didn't really know the rules. It didn't help that the commentator, Lee Jordan, kept going off topic and admiring one of the female Gryffindor players.

"Why are we cheering?" Nico whispered to Neville as the crowd erupted.

"Angelina got the Quaffle through the Slytherin hoops, so we win ten points," Neville explained.

Neville began explaining the rules in more depth as the game continued. The Slytherins had just scored their first goal when Hermione spotted something amiss. "What's Harry doing?" she wondered aloud.

Harry was flying higher and higher away from the game, his broom jerking strangely. Then it began rolling over. After a particularly wild jerk, Harry swung off his broom and was left hanging by one hand.

"He can't be doing that on purpose," Neville said, swallowing hard. "Someone must have tampered with his broomstick."

"Do you think he's going to fall?" Nico asked.

"Gee, could you sound a little more hopeful?" Leo said sarcastically, eyes on Harry. "I should have made everyone parachutes," he added under his breath.

"Must be some sort of curse," Hermione muttered, her eyes narrowed. "Probably requiring constant eye contact…"

"Eye contact?" Leo repeated, his face lighting up. "Easy fix for that." He pulled a remote out of his pocket and pressed a button. The field was suddenly obscured by smoke that smelled oddly of potato chips. A general outcry went up from the crowd as they tried to figure out what had happened.

After about a minute, the smoke dissipated to reveal Harry back on his broom and diving toward the ground. He suddenly clapped his hand to his mouth, looking like he was about to be sick. He hit the ground on all fours and coughed up something gold. "I've got the Snitch!" he yelled, waving it above his head. The Gryffindors burst into cheers.

Several hours later, the teachers gave up on figuring out where the smoke had come from. The Gryffindors gleefully began a party in Gryffindor Tower. Nico tried to slip away from the crowd, but Harry and Ron cornered him.

"So…what was that you were saying earlier about Harry falling off his broom?" Ron demanded, arms folded.

"You really think I did that?" Nico retorted. "I'm allergic to broomsticks, or have you forgotten?"

"Allergic," Ron snorted. "That's an interesting way of putting it."

"Just because you can't fly on one, that doesn't mean you can't curse one," Harry added. "How many times have you been alone in our dormitory while my broomstick was in my trunk?"

Nico rolled his eyes. "Please. If I really wanted to sabotage your broomstick, I'd make you fall off during practice when there are fewer people around to save you. You have any other stupid accusations to make, or are we done here?"

Harry stepped aside, but continued giving Nico the stink-eye. "We're not done. Far from it."

Nico rolled his eyes again. "Whatever." He walked up to the dormitory and pulled out an Ancient Greek book about the first Titan War.

That night, Nico dreamed that Snape was pacing in an office full of moving paintings and spindly silver contraptions. Dumbledore sat behind a desk, watching Snape.

"…how long are you going to let this continue?" Snape was saying. "First the troll, and now this…he's endangering the students!"

"Unfortunately, we have no proof," Dumbledore replied. "If I sack a teacher without just cause, I'm sure Lucius Malfoy would be more than happy to have me removed on charges of wrongful termination, and then where would this school be?"

Snape glared at Dumbledore. "He provided a troll for the protections, then he apparently fainted in fear of a troll that mysteriously gained entrance to the castle. Is that not proof enough?"

"Circumstantial," Dumbledore said blandly.

"He tried to head toward the third floor on Halloween, I'm sure of it," Snape growled. "If Granger and di Angelo hadn't found that troll so quickly…"

"…then perhaps Quirrell would have gotten through the trap door that night," Dumbledore interrupted. "It does not do to dwell on what might have been. And besides, I fear that Quirrell is not alone. We must watch until we know more of this plot."

When he woke up, Nico immediately shadow-traveled to the Defense against the Dark Arts classroom, looking for something of Quirrell's. He found a spare turban in a desk drawer. He picked up the turban and shadow-traveled to the forbidden corridor. The three-headed dog wagged his tail and tried to give Nico a sloppy bath.

"Hey, there, buddy," Nico said softly. He held up the turban. "You smell this? Belongs to a very bad man. If he tries to get through that trap door, you bite him, understand?"

The dog cocked his heads.

Nico held up the turban again and growled slightly. "Bad turban. Bad man."

One of the heads growled in response.

Nico nodded. "Good boy."

Nico returned the turban to the desk where he'd found it, then shadow-traveled back to Gryffindor Tower. He collapsed into bed and slept until nearly noon, drained from so many shadow-jumps in quick succession.

Quirrell continued to act jumpy in classes, though Nico could swear that he sometimes caught Quirrell giving him suspicious looks. Harry glared at Nico whenever they were in the same room, a favor which Nico readily returned. Then as the Christmas holidays approached, Hermione invited Nico to come home with her for Christmas.

"No thanks," Nico replied. "I wouldn't want to attract monsters to your house."

"Is it really that bad?" Hermione asked. "Even if you're not looking for trouble?"

"Trouble finds me. Thanks, but I'll stay at Hogwarts."

"I could stay too, then," Hermione offered. "I wouldn't want you to be stuck alone with Harry and Ron."

"No, go to your parents. At least you can spend Christmas with them."

"If you're sure," Hermione said reluctantly.

The day before term ended, Hermione and Nico ran into Hagrid on their way to the library. "Oi, di Angelo, got a bone to pick with you," Hagrid said. "Harry and Ron tell me you tamed Fluffy. How'd you do that without music?"

"Fluffy?" Nico repeated, confused.

"Big dog? Three heads?"

"His name is Fluffy?" Hermione said incredulously.

"Yeah—he's mine—bought him off a Greek chappie I met in the pub las' year—"

Nico frowned. "Did he happen to have three chests?"

Now it was Hagrid's turn to be confused. "Three chests?"

"Ran into a guy who was selling monsters on the black market last summer," Nico explained. "He tried to sell me too."

Hagrid stared at him. "What were you doin', gettin' involved with black market dealers?"

"Long story," Nico shrugged.

"Didn't yer parents never warn yeh to be careful o' folks like that?"

Nico scowled. Hermione quickly spoke up. "Don't get him started on his parents. It's not a happy story."

Hagrid narrowed his eyes, then caved. "Fine. But yeh still haven' answered my question. How'd you tame Fluffy?"

"Not the first three-headed dog I've met. They just seem to like me."

"Yeh've met another three-headed dog?" Hagrid asked, looking interested. "Where?"

"I'm not here to discuss my life story," Nico said grumpily. "Can I go do my homework now?"

"Fine," Hagrid acquiesced. He moved out of the way.

A few hours later, Nico had finished his Potions homework and began skimming the Greek Potions textbook he'd found. "Amazing, the stuff you can make," he murmured to himself.

"Amazing, the things you can't spell," Hermione replied, proofreading his work and shaking her head. "Tell you what, I'm buying you a spell-checking quill for Christmas."

"They make those?" Nico asked, surprised.

"Yes. Just don't use it on exams though, that's considered cheating."

"Okay." Nico suddenly stiffened. "What are you doing here, Harry?"

There was a moment's silence before Harry answered, still out of sight behind a bookshelf. "None of your business." His footsteps retreated.

"Do you realize how creepy it is when you do that?" Hermione complained. Nico had a disconcerting habit of greeting Harry when he shouldn't have known Harry was there.

Nico grinned wolfishly. "Wish I could see the look on his face."

Hermione sighed and continued proofreading Nico's homework. By now she was fairly certain that Nico really could sense something off about Harry, though she wasn't sure what. Harry had survived the Killing Curse as a baby; that might give off a bad vibe to a child of Hades. Or maybe there was actually something evil about Harry.

"There's a Draught of Memory Restoration!" Nico exclaimed suddenly.

"What?"

"A potion that restores lost memories! If I could make that…hey!" The shadows suddenly darkened and swallowed Nico.

"Nico?" Hermione asked uncertainly. The shadows dissipated, but Nico's chair remained decidedly empty. "Nico?" Still nothing. Hermione swallowed and looked up at the ceiling. "Hades? Er…" She looked down at the floor instead. "Lord Hades…please give him back? I'm sure I could stop him from making the potion…or you could just make him forget he read that…or something…" She swallowed again. "Please don't take Nico away."

There was still no response. She waited until the library closed for the night, but Nico did not reappear.

The next day at breakfast, Hermione approached Neville. "Have you seen Nico?"

"Not since Charms yesterday, why?"

"He didn't come back to Gryffindor Tower last night?"

"I dunno. I went to bed early. Something wrong?"

Hermione grimaced. "I don't know."

As soon as Snape called the class to attention, he noticed Nico's absence. "Where is Mr. di Angelo?" he asked Hermione.

"I don't know, sir, I haven't seen him since he left the library last night." Hermione felt it was probably best not to mention how Nico had left the library.

"I see." Snape turned to Harry. "Was he in your dormitory this morning?"

"No, sir."

"Did he return to your dormitory last night?"

"No, sir."

"And you didn't think to report this to a teacher?" Snape asked, raising his eyebrows.

"Er…no, sir."

"Your lack of concern for your classmate appalls me. Ten points from Gryffindor." Snape returned to his desk and gestured to the board. "You will be making an Herbicide potion today. I expect you to work diligently while I investigate Mr. di Angelo's disappearance."

By the end of the day, Hermione had been questioned by Professors McGonagall and Dumbledore as well, and there was still no sign of Nico. She reluctantly packed her trunk for the holidays, wondering if she would ever see her friend again.

Nico retrieved his kitten and his trunk before collapsing onto his bed in the Underworld, exhausted. Recovering his father's new sword had thoroughly sapped his energy. Still…they'd gained a potential ally that day. Nico resolved to spend Christmas vacation making friends with "Bob" the amnesiac Titan.

A/N: Just to be clear, Nico's disappearance was due to his involvement in the events of Percy Jackson and the Sword of Hades.